Finding the Fourth Proportional to 105.02, 145.09 and 72.36

Step by Step Solution

1. Step 1: Write the proportion equation
   105.02 : 145.09 = 72.36 : x
2. Step 2: Convert to fraction form
   105.02/145.09 = 72.36/x
3. Step 3: Cross multiply
   105.02x = 145.09 × 72.36
4. Step 4: Simplify right side
   105.02x = 10,498.71
5. Step 5: Solve for x
   x = 10,498.71/105.02
6. Step 6: Final answer
   x = 99.97